This invention generally relates to furans and more particularly to 2,5-dipicrylfurans.
Use of explosives in many different types of devices is widely known in the prior art. However, despite the large number of explosives that are known, there are relatively few that can withstand temperatures of about 230.degree. C without substantial deterioration. Because explosives in many specialized uses are subjected to temperatures as high as 230.degree. C, there has been a constant search for explosive materials which will not substantially deteriorate when exposed to these high temperatures.
U.S. Pat. No. 3,923,830 issued to Micheal E. Sitzmann and Joseph C. Dacons discloses 2,5-dipicryl thiophenes of the formula ##STR2## wherein R.sub.1 and R.sub.2 are selected from the group consisting of H and NO.sub.2. These 2,5-dipicryl thiophenes are energetic explosives which can be exposed to high temperatures in the range of 230.degree.-260.degree. C without substantial deterioration.
It is desirable to find other thermally stable explosive compounds with still greater energy. Because the 2,5-dipicryl thiophenes are fuel [C,H,S] rich and oxidizer [O] poor, increasing the oxygen content of the compound should increase the energy of the explosive. Adding a separate oxidizer to these compounds is undesirable because an explosive mixture can not be as uniform as a single explosive compound and the components of the mixture will tend to separate during storage. On the other hand, it is unlikely that the oxygen content of 2,5-dipicryl-3,4-dinitrothiophene can be increased because the only unsubstituted positions are on the deactivated picryl rings. Even if substitution were possible, it is doubtful that the products would have high thermal stability.
It would be desirable, therefore, to find new explosive compounds with high thermal stability but greater energy.